'Rock snot' shows up in New England rivers

Invasive algae also found in South Dakota

Invasive algae also found in South Dakota

August 26, 2007

STOCKBRIDGE, Vt. (AP) - It looks like a clump of soiled sheep's wool, a cottony green or white mass that's turning up on rocks and river bottoms, snarling waterways. Already a scourge in New Zealand and parts of the American South and West, the aquatic algae called “rock snot” is creeping into New England, where it is turning up in pristine rivers and alarming fishermen and wildlife biologists. “It scares me,” said Lawton Weber, a fly fishing guide, who first spotted it on the Connecticut River in northern Vermont in June. “It's an aesthetic eyesore when it's in full bloom mode and its impact on the trout population is going to be significant.” Over the past 10 years, the algae with a scientific name of Didymosphenia geminata, or didymo, has turned up in California, Washington, Alaska, Idaho, Montana, Nevada, Utah, Wyoming, Colorado, the Dakotas, Missouri, Arkansas and Tennessee. “We're starting to realize it's all over the place,” said Karl Hermann, a regional waste monitoring and assessment coordinator for the Environmental Protection Agency in Denver. What started out in Vancouver Island in British Columbia “has suddenly just skyrocketed,” he said. The algae has the potential to bloom into thick masses with long stalks, blanketing the bottoms of some streams, threatening aquatic insect and fish populations by smothering food sources. There's no easy way to get rid of it. Experts say the only hope is to keep it from spreading. But that's a lofty challenge, since a single cell carried on absorbent fishing gear or clothing can be transferred - unknowingly - into other waters. Vermont and New Hampshire have launched a radio campaign urging river users to scour their boats and clean their gear. “Please don't take chances, disinfect your fishing gear,” said Scott Decker, program supervisor with the New Hampshire Fish and Game Department. It's unknown yet what effect, if any, the algae will have on fish populations, according to Sarah Spaulding, an ecologist with the U.S. Geological Survey and the EPA. But many are concerned. “Once you remove (insects), young fish don't have anything to eat,” said David Deen, a Vermont lawmaker who is a fishing guide and river steward for the Connecticut River Watershed Council. “Growth is slowed at best, and at worst they could starve to death.” In South Dakota, the algae is suspected of decimating brown trout populations in some spots.